Background: Academic boredom is ubiquitous, and it leads to a range of adverse learning outcomes. Given that students often make estimates of how boring lectures are, does anticipating a lecture to be boring shape their actual experience of boredom? Aims: The current research investigated whether anticipated boredom intensifies subsequent boredom felt in lectures. Samples: We recruited undergraduate students to participate in three studies. Methods: Study 1 (N = 121) and study 2 (N = 130) were conducted in natural university lecture environments. We found that students who anticipated a lecture to bore them more subsequently felt more bored by it. In study 3 (N = 92), we experimentally manipulated anticipated boredom before participants watched a lecture video. We found that those who were led to anticipate higher levels of boredom felt more bored by the video. Results and Conclusions: Results converged to indicate that the mere expectation that a lecture will be boring may be sufficient to exacerbate its subsequent occurrence. We discuss these findings in the contexts of affective forecasting and education.